Tidewater Gardening - October 2009
The Chill Is In The Air
K. Marc Teffeau
The morning air is crisp. The shadows in the afternoon are longer and we notice a distinct change in the environment all around us. Although the arrival of October signals that winter is just around the corner, to me it is one of the most pleasant months of the year. You can get out and do the work in the yard and not have to suffer from the humidity of summer.
In talking with some of our wholesale nursery growers in September, they were hoping for an uptick in fall sales to help overcome somewhat of a dismal spring sales season. To help them along I like to remind folks that October is an excellent time to plant trees and shrubs.
Most homeowners think of spring as the best time to plant trees and shrubs in the landscape. However, October and November are generally considered the best time for moving plants around. For whatever reason, you can see trees and shrubs that did not make it through the summer and now is a good time to replace them. Garden centers and nurseries usually stock a good selection of woody plants this time of year.
You can transplant deciduous trees and shrubs after they become dormant, usually after the first or second hard frost. You can also transplant evergreen trees and shrubs earlier in the fall before they become dormant. The exception to fall transplanting is pine seedlings. They do very poorly when transplanted in the fall because they are not able to develop a good root system before the winter sets in.
Red is one of the dominant fall colors that we see in our temperate climate. Trees that turn red include dogwood, sweet gum and red and scarlet oak. Remember that fall color is more strongly influenced by the tree’s genetic makeup than by the environment, although the type of growing season the tree has been through has an effect on the intensity of the color.
Trees selected in the fall when they are in full color can be expected to produce the same colors in future years. Red maple is one of the standard trees for good fall color. Cultivars of red maple that display outstanding colors include ‘Red Sunset’, ‘October Glory’ and ‘Autumn Flame.’
October is a good time to do maintenance of the trees and shrubs in the landscape. While you can still identify them easily, prune dead and diseased branches from trees and shrubs. Old, fallen leaves can contain disease inoculum for next year’s plant infections. Remove any infected debris from around the plant’s base and dispose of it.
We usually recommend mulching newly planted trees and shrubs to reduce weed problems and to conserve moisture. In the fall, however, it is usually a good idea to wait to mulch until after the soil temperatures have reached 32°. Mulches applied too early can do more harm than good.
Mulch is used to keep soil temperatures constant and prevent frost heaving, not to keep it warm. In October the trees and shrubs start to harden for the upcoming cold weather. To encourage this process, remove mulch from around the stems of shrubs and trees. This will also discourage mice and vole damage to the stems during the winter.
October is also the time to hold a bagworm party to remove the bags from the trees. This will help reduce the amount of spring hatch from over-wintering eggs in the bags and reduce the amount of spraying you may have to do next year.
Now is the time to dig tender summer bulbs like dahlias, gladiolus, tuberous begonia and cannas and store them for the winter. These plant parts require winter protection of they are going to be used year after year. As soon as frost blackens the tops of dahlias, cut them back, dig them up and let dry in the sun for a day. After they are dry, carefully clean off the excess soil and store the tubers in baskets or flats of peat moss or crumpled newspaper.
Gladiolus should be lifted with the tops on and allow them to ripen or cure for several weeks. Discard any plants that appear diseased, crippled or mottled. The best conditions for curing are temperatures of 85° to 90° and a relative humidity between 40% and 50%.
Circulating air through and around the corms by means of a fan will hasten the curing process. This process usually takes about two weeks. When they are dry, separate the old shriveled corms from the new ones and discard them, remove some of the old husks and cut the tops back flush with the new corm.
Separate your corms or cormels from the parent corms if you want to increase your supply of a particular cultivar. Store the corms on wire mesh trays or in mesh bags. A pair of discarded panyhose or a fine mesh onion bag makes an excellent storage bag. Hang the bag up to allow for good air circulation and to keep the mice out.
If you planted tuberous begonias outside in pots, let them dry by withholding water or wait until the leaves turn yellow. Then, either remove the tubers from the pots or bring the entire pot in and store in a cool, dry location away from frost and freezing temperatures.
If you planted them in beds, dig them up and let them dry naturally. When they are dry, cut the tops back and store them in baskets or boxes of peat moss or crumpled newspaper.
Tubers of caladiums are dug and stored the same way as tuberous begonias.
Rhizomes of cannas should not be dug until the tops have been killed by a light frost. To store, cut off the stems of the plants and dig the rhizome clumps using a garden spade. Allow the clumps to dry and store them with soil still clinging to the rhizomes in an area where they will not freeze.
The best storage temperature for these bulbous plants, except for caladiums, is 40 to 50° during the winter. Caladiums must be stored at temperatures above 60°.
Temperature is a very important factor in the proper storage of this plant. Check them occasionally for rot or mouse damage. Discard those that have rotted and control mouse problems with mouse bait in the storage area.
As the first frost hits and plants start to die, pull out the annuals and cut back the perennials. Dirty flower beds harbor insects and disease that will over-winter in the stems and roots of your plants if they are allowed to remain in the ground. It can also be said that flower beds full of old dead plants detract from the clean neat appearance of your home. Shred the plant materials with a shredder or the lawn mower and put them in the compost pile.
If your flower beds are primarily annuals, a steel rake is a useful tool for not only raking up the debris, but can also be useful for pulling out the dead or dying plants.
If your perennial beds are inter-planted with annuals, it is best to hand pull the annuals, trim back the perennials with a sharp pair of lawn clippers and clean out your garden with a lawn rake.
In October homeowners may get concerned about narrow-leafed evergreens, like pine and spruce, turning brown and “dying.” It usually turns out that the browning is occurring on the inside foliage of the plant. The new foliage on the outside of the branches looks fine.
This is a natural phenomenon since each year these trees grow a new set of needles in the spring and drop their oldest set in the fall. In some trees like white pine and arborvitae, the dying of the foliage takes place rather suddenly and the trees present an alarming appearance which usually lasts for only a short time.
As soon as the dead leaves have been brought down by strong winds or heavy rain, the trees regain their normal appearance. No harm is done to the trees by the loss of these needles.
In the vegetable garden, October is clean-up time. Remove any dead or dying plants. Compost the debris if they do not contain disease problems. Use a shredder if available to cut up the plant debris before placing them in the compost pile. This will encourage faster decomposition of the plant material. If you do not have a shredder and have only a small amount of materials, run over it with the lawn mower. This works very well if you have a bagging mower. Then rake up the cut materials or empty the bag into the compost pile.
If the ground is dry and workable, and the garden site is not subject to soil erosion, consider doing a fall plowing and letting the ground lay exposed over the winter. Late fall tilling can help control insects, such as the corn borer, corn earworm, cucumber beetle, squash bug and vine borer because it exposes over-wintering insect to winter conditions. It also makes soil preparation easier in the spring.
Another alternative is to mulch the entire garden in the fall with straw to a depth of to 6 inches. Then in the spring, only pull back the mulch in the areas that you plan to plant. You will need to do this a couple of weeks before planting, however, to give the soil time to warm up.